Whether renovating a period property or building a modern home, window dimensions are crucial in achieving the perfect balance of natural light, energy efficiency, and style. Understanding window dimensions is essential in deciding the best type of window for your home improvement project.
BSF Windows explores the complexities of window sizing in the UK market in this detailed guide. From traditional sash windows to contemporary aluminium installations, we’ll help you navigate standard window dimensions and practical considerations for your window project.
Understanding Window Measurements
Accurate measurement involves more than simple width and height calculations. Today’s window installations require a precise understanding of frame depths, reveal measurements, and opening mechanisms. Professional window installers consider every millimetre crucial, as even a little bit of discrepancy can affect performance and appearance. While measurements are typically provided in millimetres for precision, we’ve included imperial conversions for comparison with older property specifications.
How to Measure for a New Window
To measure for a new window:
- Measure the width at three points (top, middle, and bottom of the frame)
- Measure the height at three points (left, centre, and right side)
- Check diagonal measurements to ensure the opening is square
Remember, while these measurements provide a good guide to what windows will be possible for you, professional window installers, including those from BSF Windows, will always conduct their own survey before installation.
Standard Casement Window Sizes
Casement windows are a popular choice that still dominate the UK residential market, offering exceptional versatility, affordability, and low maintenance. At BSF Windows, our casement windows combine versatility with outstanding performance. Available in both uPVC and aluminium options, these windows feature excellent thermal efficiency for lower energy bills, while robust security features provide complete peace of mind. Our casement windows can be customised with various colours and finishes to complement any property style.
Standard Casement Window Size Chart
| Metric (mm) | Imperial (inches) | Imperial (feet & inches) | Common Use |
|---|---|---|---|
| 625 x 745 | 24.6″ x 29.3″ | 2’0″ x 2’5″ | Small bathrooms |
| 625 x 1045 | 24.6″ x 41.1″ | 2’0″ x 3’5″ | General use |
| 925 x 1045 | 36.4″ x 41.1″ | 3’0″ x 3’5″ | Most common |
| 1200 x 1045 | 47.2″ x 41.1″ | 3’11” x 3’5″ | Large rooms |
Sliding Sash Window Dimensions
Our uPVC sliding sash windows are designed to mimic the look of traditional timber windows but with modern benefits. They offer outstanding thermal performance and advanced security features and are backed by our 10-year warranty. With customisable options including various woodgrain finishes and colour choices, these windows are ideal for both heritage properties and contemporary homes seeking that classic appeal.
Standard Sash Window Size Chart
| Metric (mm) | Imperial (inches) | Imperial (feet & inches) | Common Use |
|---|---|---|---|
| 915 x 1340 | 36″ x 52.8″ | 3’0″ x 4’5″ | Standard size |
| 1065 x 1340 | 42″ x 52.8″ | 3’6″ x 4’5″ | Wider option |
| 1220 x 1765 | 48″ x 69.5″ | 4’0″ x 5’10” | Period properties |
Flush Sash Window Dimensions
Flush sash windows are designed to sit flush within their frames, creating a sleek, seamless appearance that suits traditional properties. Flush sash windows recreate the look of traditional timber windows while offering modern benefits and a contemporary design twist.
Standard Flush Sash Window Size Chart
| Metric (mm) | Imperial (inches) | Imperial (feet & inches) | Common Application |
|---|---|---|---|
| 488 x 1045 | 19.2″ x 41.1″ | 1’7″ x 3’5″ | Small openings and cottages |
| 625 x 1045 | 24.6″ x 41.1″ | 2’0″ x 3’5″ | Standard residential use |
| 925 x 1045 | 36.4″ x 41.1″ | 3’0″ x 3’5″ | Larger rooms and feature windows |
Bay and Bow Window Dimensions
Bay and bow windows are architectural features that project outward from your home’s exterior wall, creating additional interior space while flooding rooms with natural light. While similar, bay windows typically feature a larger central window with two smaller windows at angles on either side, while bow windows create a gentler curve using four to six windows of equal size. At BSF Windows, we install both styles across Surrey and Sussex, and surrounding areas.
Standard Bay Window Size Chart
| Metric (mm) | Imperial (feet & inches) | Configuration |
|---|---|---|
| 2400 x 1200 | 7’10” x 3’11” | 3-section standard |
| 3000 x 1200 | 9’10” x 3’11” | 3-section wide |
| 3600 x 1200 | 11’10” x 3’11” | 5-section bay |
Standard Bow Window Size Chart
| Metric (mm) | Imperial (feet & inches) | Configuration |
|---|---|---|
| 2700 x 1200 | 8’10” x 3’11” | 4-section standard |
| 3300 x 1200 | 10’10” x 3’11” | 5-section classic |
| 3900 x 1200 | 12’10” x 3’11” | 6-section large |
Tilt and Turn Window Dimensions
Tilt and turn windows are a practical solution that offers two different opening styles in one window. As the name suggests, these windows can either tilt from the top for secure ventilation or turn entirely inward for easy cleaning and maximum airflow. At BSF Windows, we offer these versatile windows in both uPVC and aluminium options, with the aluminium versions featuring particularly slim sightlines for a more contemporary look.
The ability to clean both sides of the glass from inside your home makes these windows especially popular for upper floors or hard-to-reach areas.
Standard Tilt and Turn Size Chart
| Metric (mm) | Imperial (inches) | Imperial (feet & inches) | Common Application |
|---|---|---|---|
| 600 x 900 | 23.6″ x 35.4″ | 2’0″ x 2’11” | Small bathrooms and utility rooms |
| 900 x 1200 | 35.4″ x 47.2″ | 2’11” x 3’11” | Bedrooms and living spaces |
| 1200 x 1500 | 47.2″ x 59.1″ | 3’11” x 4’11” | Statement windows and larger openings |
Modern and Traditional Window Sizes
The size of windows has changed significantly over the years. Traditional properties typically feature smaller, more frequently spaced windows. These homes often have windows around 900mm wide, particularly in Victorian and Georgian properties where maintaining period proportions is essential.
Modern homes, by contrast, tend to favour much larger types of windows to create bright, open spaces. Today’s double glazing and improved frame materials mean we can now safely install windows up to two meters wide in some cases. Floor-to-ceiling windows, wide bay configurations, and panoramic designs have become increasingly popular to create unique spaces.
Whether matching existing period windows or planning a contemporary extension, understanding these common sizes helps ensure your new windows complement your property’s style.
Improving Your Home with BSF Windows
BSF Windows brings decades of expertise to every project, helping homeowners navigate the complexities of window selection and installation. Our comprehensive range includes everything from heritage timber windows to popular uPVC windows and modern aluminium windows, all available in a range of sizes to suit your specific requirements.
With over a decade of experience serving Surrey, Sussex and surrounding areas, BSF Windows has built a strong reputation for quality window installations at competitive prices. Our approach combines expert craftsmanship with exceptional customer service, ensuring every installation meets our high standards.
The best way to view and use our extensive range of windows is by visiting our showroom. Here, you can talk to our friendly team of experts and discuss your options. You can find this at 31-33 Station Road, Horley, Surrey, RH6 9HW.
To arrange a no obligation quote, call us on 01293 408 713, email us at bsfwindows@gmail.com or use our online contact form.